Field of Invention
The present invention relates to a coupling connector used in an irrigation system and, in particular, to a coupler used for guiding water flow of the irrigation system and connecting to hoses or sprayers.
Description of Related Arts
Refer to FIG. 6 and FIG. 7, a conventional coupler 1a includes a base 5a, a connecting portion 11a and a retaining member 4a. The base 5a is tubular and having a space for mounting the connecting portion 11a and the retaining member 4a. The connecting portion 11a is disposed with a push portion 111a and a tube 15a while the tube 15a has a first channel 52a and a second channel 151a. The first channel 52a is one end of the tube 15a extended to the base 5a. The first channel 52a is set with a threaded portion 51a and a retaining wall 53a having an insertion hole 531a. The retaining wall 53a is used for covering the first channel 52a. The second channel 151a has an opening end 12a. A spring 13a is fitted over and close to the opening end 12a. Thus an insert 6a for connection to sprayers or hoses can be mounted into the second channel 151a. 
The retaining member 4a is arranged between the second channel 151a and the first channel 52a. The retaining member 4a consists of a flange 41a and a column head 42a formed by extending the flange 41a. The diameter of the flange 41a is larger than the diameter of the column head 42a. A third channel 44a is disposed in the column head 42a and a second seal ring 3a is arranged around the column head 42a. The insertion hole 531a of the retaining wall 53a is sealed by the second seal ring 3a of the column head 42a. A first seal ring 2a is set between the flange 41a of the retaining member 4a and the retaining wall 53a of the threaded portion 51a. A plurality of through holes 43a is radially disposed on the column head 42a so that the third channel 44a is communicating with the second channel 151a or the first channel 52a by the through holes 43a. 
Moreover, the first channel 52a is used for connecting to a water supply means while the second channel 151a is used to mount the insert 6a. The insert 6a is used to connect an outflow tube or sprayers for water output.
When the user mount the insert 6a into the coupler 1a and the insert 6a is assembled with the connecting portion 11a to allow water at the end of the threaded portion 51a flowing from the first channel 52a to a fourth channel 64a of the insert 6a to be output, the insert 6a is axially mounted into the second channel 151a of the connecting portion 11a. Then the retaining member 4a is pressed downward to the first channel 52a so that one end of the second seal ring 3a arranged at the column head 42a of the retaining member 4a is away from the insertion hole 531a and one of the through holes 43a of the column head 42a is communicating with the first channel 52a. Thus the water flow from the first channel 52a can be guided into the through holes 43a of the retaining member 4a and then flows through the fourth channel 64a of the insert 6a to be output.
In the conventional coupler, the first seal ring 2a is arranged at the second channel 151a and located between the flange 41a of the retaining member 4a and the retaining wall 53a of the threaded portion 51a. When the insert 6a is pressed downward toward the retaining member 4a, the insert 6a will firstly lean against the upper edge of the flange 41a of the retaining member 4a, instead of the first seal ring 2a. Thus a part of water flow will be sprayed out of a gap between the second channel 151a and the insert 6a. The sprayed water flow will not stop until the insert 6a leans against the first seal ring 2a. Thus the user can be splashed by the sprayed water flow.